Gliese 22

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Gliese 22
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia
Gliese 22 A
Right ascension 00h 32m 29.4336s
Declination +67° 14′ 08.409″
Apparent magnitude (V) 10.29
Gliese 22 B
Right ascension 00h 32m 29.575s
Declination +67° 14′ 04.63″
Apparent magnitude (V) 12.19
Gliese 22 C
Right ascension 00h 32m 29.4s
Declination +67° 14′ 08″
Apparent magnitude (V) 13.2
Spectral type M2.5Ve / M3V
U−B color index 1.16
B−V color index 1.54
R−I color index 0.99
Variable type Flare stars
Radial velocity (Rv) 10 km/s
Proper motion (μ) RA: 1739.0 mas/yr
Dec.: -224.93 mas/yr
Parallax (π) 99.35 ± 2.17[1] mas
Distance 32.8 ± 0.7 ly
(10.1 ± 0.2 pc)
Absolute magnitude (MV) 11.83
Companion Gliese 22 B
Period (P) 320 yr
Semi-major axis (a) 4″
Inclination (i) 140°
Companion Gliese 22 C
Period (P) 16 yr
Semi-major axis (a) 0.5″
Mass 0.4 M
Radius 0.5 R
Luminosity 0.04 L
Temperature 2000–3500 K
Other designations
2MASS J00322970+6714080, BD+66° 34, CCDM J00325+6714, Gl 22, HIP 2552, LFT 47, V547 Cassiopeiae
Database references
Exoplanet Archive data
Extrasolar Planets

Gliese 22, also catalogued V547 Cassiopeiae, is a hierarchical star system approximately 33 light-years away in the constellation of Cassiopeia. The system consists of two red dwarf stars, Gliese 22A and Gliese 22B in an outer orbit of about 320 years, and a brown dwarf, Gliese 22C, which orbits Gliese 22A in about 16 years. As of 2008, it was announced that a possible extrasolar planet, Gliese 22B b, or brown dwarf orbits Gliese 22B but this is currently unconfirmed.

Planetary system[edit]

The Gliese 22 planetary system
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b (unconfirmed) 16 MJ 5,500 0


  1. ^ van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357 

External links[edit]